The war-weary people of Somalia have survived 16 years of anarchy and bloodshed, but even they haven't seen fighting this intense since the overthrow of dictator Mohamed Siad Barre in 1991.
Mortars have crashed into targets across the capital, Mogadishu, for the past four days. The city's hospitals are overflowing, and more than 50,000 people have fled, according to aid agencies.
On Sunday, the Ugandan Army said one of its soldiers had been killed – the first African Union peacekeeper to die – during clashes in Mogadishu.
But civilians have been the main victims since a shaky six-day cease-fire broke down on Thursday when Ethiopian and Somali government troops, backed by tanks and helicopters, launched a major offensive to clear Mogadishu of insurgents linked to the country's ousted Union of Islamic Courts (UIC).
The offensive has focused on areas of Mogadishu controlled by a clan that is a major supporter of more radical elements of the UIC, which ruled the capital for six months before being driven out in December. That clan is the Habr Gedir, a branch of the larger Hawiye clan, and on Sunday clan leaders announced a truce with Ethiopian military officials.
Skepticism of peace deal
Despite the announcement, however, gunfire rang out across the city Sunday, and one analyst, speaking on condition of anonymity because he works as an adviser to the Transitional Federal Government, said the truce is unlikely to hold.
"Basically this raises all the same problems we have seen with previous peace deals," he says. "The Hawiye elders really have very little leverage or control over the young and the radicals."
Abdullahi Ali Hassan, director of the Center for Development and Education, a Somali non-governmental organization, says the fighting is intense even by Mogadishu's skewed standards.
"It's the heaviest fighting since the overthrow of Siad Barre in 1991. There are wounded people everywhere and many deaths," he said by telephone from his office in Mogadishu.
He added that markets had closed, making it impossible for residents to get food or water, and that thousands of people had been made homeless by the shelling.
Mr. Hassan says he has 10 families now living in his home after they were bombed out of theirs.
On Friday, insurgents downed an Ethiopian helicopter gunship – a vivid reminder of when militias shot down two American Black Hawks in 1993.
And over the weekend, doctors in the city's hospitals said they were no longer able to cope with the numbers of wounded.
"We are operating with only half our surgeons here, and the doctors who are here have now been working without relief for the last three days," Sheikhdon Salad Elmi, director of the city's main Madina Hospital, told Reuters.
Sixteen years of turmoil
Somalia has been beset by violence since the overthrow of Mr. Barre in 1991.
Clan-linked warlords carved the country into a series of personal fiefdoms, making it all but impossible for any central authority to take control.
That changed last year when militias linked to the UIC seized control of Mogadishu and a swath of southern and central Somalia.
They were ousted at the end of December by Somali government forces and troops from neighboring Ethiopia.
Ethiopia – with the tacit support of the US – feared a hard-line Islamic state would become a haven for Al Qaeda terrorists. But since then a weak interim Somali government has struggled to impose order on Mogadishu.
In his most recent briefing on Somalia, the US ambassador to Kenya, Michael Ranneberger, described an "insecurity soup" operating in the city. He said fighters loyal to the city's warlords and bandits had reemerged to take advantage of its anarchic state.
But he also said that Al Qaeda was encouraging the rump of the ousted UIC to reorganize around Aden Hashi Ayro, a militant Islamist militia commander. He is believed to have been trained in Afghanistan and to be linked to the murder of Western journalists and aid workers in Somalia.
So far the AU has sent 1,200 Ugandan troops to help the government and pave the way for the withdrawal of Ethiopian troops, seen by many as an invading power. Other African nations have balked at sending more peacekeepers to boost the AU force to its planned strength of 8,000.
The residents of Mogadishu are not prepared to wait. Many are leaving their homes with all they can carry. The UN reports that 58,000 people have fled Mogadishu's violence in the past two months and 12,000 have left in the past 10 days.
They risk harassment or rape, according to the UN Office for the Co-ordination of Humanitarian Affairs. It is difficult for men to make the journey as it requires crossing clan lines, which would put them at risk of revenge killings.